Nowadays, various compact antennas have been developed and applied to various compact hand-held electronic devices (e.g. cellphones or notebook computers) or the wireless transmission device (e.g. the AP). For example, the planar inverse-F antenna (PIFA) or the monopole antenna that is compact, has a good transmitting efficiency, and can be easily disposed on the inner wall of the hand-held electronic device already exists, and is widely applied to various hand-held electronic devices for wireless transmission, the notebook computer or the wireless communicating device. Traditionally, the inner conductor layer and the outer conductor layer of the coaxial cable are respectively welded to the signal feeding point and the signal ground point of the PIFA so that the signal to be transmitted is output via the PIFA. The monopole antenna is one of the most traditional and classical antennas, which has a simple structure, a small size, a light weight, a low cost as well as a small standing wave coefficient, and is omnidirectional. However, in order for the monopole antenna to be applied to different bandwidths, it is necessary to increase the bandwidth of the monopole antenna. Commonly, there are two ways to increase the bandwidth of the monopole antenna. One is to load the monopole antenna, and the other is to use the planar monopole antenna. Loading the monopole antenna will cause the size thereof to be larger and reduce the radiating efficiency thereof. The planar monopole antenna has a larger impedance bandwidth, but its radiating direction has a larger change in the bandwidth and is more inconsistent. Besides, the size of the planar monopole antenna is larger.
In order to overcome the drawbacks in the prior art, an antenna structure and the manufacturing method therefor are provided. The particular design in the present invention not only solves the problems described above, but also is easy to be implemented. Thus, the present invention has the utility for the industry.